Seppuku is a form of Japanese ritual suicide by disembowelment. A second was present to decapitate the suicide, and spare them the further pain of the disembowelment. In later years, the second was allowed to use a pistol. Seppuku is also known in English as hara-kiri, a term regarded as gross and vulgar in Japanese.
While in the body of the legendary Benkei, fictional character Stevefought off the followers of Minamoto Yoritomo while his friend Minamoto Yoshitsune committed seppuku. However, when Benkei's body died, Steve became an omniscient observer, and saw that Yoshitsune had not committed seppuku, though the story ended before Steve could find out what Yoshitsune's final fate.
A Japanesebrigadier general was the senior officer available to sign a surrender treaty to the United States in 1946. The treaty was carried out after the Americans agreed to return the body of Emperor Hirohito, recently killed in action, for a formal funeral. Once the signing was completed, the brigadier ritually slit his belly to atone for the shame of surrendering.
↑'Magazine of Fantasy and Science Fiction, March/April 2021.